Just picked up a used dryer in pretty darned good shape, but a week or so after bringing it home it stopped tumbling: it just hummed a bit.

So, I replaced the circuit board and it worked again...for a few hours.

Replaced circuit board again, but this time no joy at all, just humming when I turn the start knob.

I pulled out the drum and tried starting the motor. It started slowly and ran with effort, so I ordered and installed a new one. I also found that the grease in the rear drum bearing was more like chewing gum, so cleaned and greased that with the correct grease. Unfortunately, the new motor, while seemingly running fine without the drum in place, will not turn the drum. Perhaps it does not have enough power, but why? There is no significant voltage drop when I turn knob, so I suspect some electronic part, but which one?

Thanks for any help.. I'm tired of buzzing when I try to start the thing and of my wife unhappy about wrinkled clothes....

Yep, voltage test pointed me to the problem: poor wiring (neutral is not conducting properly, probably due to rats). Now all I need to do is crawl under the settling house (basely any wiggle room remains) and run new wire in conduit. All is solved, but I wish I had found this before spending money on various parts.

Thanks for the help!